GIÁ TRỊ CỦA VIỆC PHÁT HIỆN NHANH CARBAPENEMASE VÀ MỐI LIÊN QUAN VỚI KIỂU HÌNH KHÁNG CEFTAZIDIME/AVIBACTAM Ở VI KHUẨN GRAM ÂM TẠI BỆNH VIỆN THANH NHÀN NĂM 2025

Abstract

Objectives: To identify common carbapenemase types using the O.K.N.V.I RESIST-5 and RESIST-ACINETO rapid tests, and to describe the association between carbapenemase types and ceftazidime/ avibactam (CZA) resistance phenotypes among Gram-negative bacteria isolated at Thanh Nhan Hospital in 2025. Methods: A cross-sectional study was conducted on 150 Gram-negative isolates (Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii), including 120 carbapenem-resistant and 30 carbapenem-susceptible strains. Carbapenemase types (KPC, NDM, VIM, OXA-48, OXA-23/40/58) were detected using RESIST-5 and RESIST-ACINETO. CZA susceptibility was determined by automated systems and broth microdilution. Results: Carbapenemase positivity was 89.2% in carbapenem-resistant strains and 10% in susceptible strains (p < 0.001). In K. pneumoniae, OXA-48 predominated (56.8%), followed by KPC (45.9%) and NDM (37.8%). In P. aeruginosa, KPC (59%) and NDM (43.6%) were the main enzymes. A. baumannii primarily carried OXA-23 (77.3%). NDM strongly predicted CZA resistance in both P. aeruginosa (PPV 91.7%; OR = 13.75; p < 0.01) and K. pneumoniae (PPV 100%; OR = ∞). Conversely, KPC was associated with CZA susceptibility in K. pneumoniae (PPV 80%; OR = 0.125; p < 0.01) and P. aeruginosa (PPV 78.9%; OR = 0.014; p < 0.01). Conclusions: Rapid carbapenemase detection provides valuable guidance in the early selection of CZA before routine susceptibility results are available. The strong correlation between carbapenemase type and CZA phenotype highlights the clinical importance of rapid enzyme detection in optimizing antimicrobial therapy and infection control.